Feed and tail stock for grinding machines



prifi 30, 1935. AM

FEED AND TAIL STOCK FOR GRINDINL MACHINE Filed Feb. 15, 1933 4 Sheets-Sheet l April 30, 1935. J. R. DUNHAM FEED AND TAIL STOCK FOR GRINDING MACHINE Filed Fb, 15, 1953 4 Sheets-Sheet 2 3mm 0 tfohn Rl unfiwm April 30, 1935. J. R. DUNHAM FEED AND TAIL STOCK FOR GRINDING MACHINE Filed Feb. l5,' 1 933 4 Sheets-Sheet 3 grwc/wto'n GHQ: new

April 30, 1935.

J. R. DUNHAM FEED AND TAIL STOCK FOR GRINDING MACHINE Filed Feb. 15, 1953 4 Sheets-Sheet 4 Patented Apr. 30, 1935 1,999,321

UNITED STATES PATENT OFFICE FEED AND TAIL STOCK FOR GRINDING MACHINES John Ryer Dunham, New Brunswick, N. J.

Application February 15, 1933, Serial No. 656,933

45 Claims. (Cl. 51-108) My invention relates to grinding machines and Figure 4 is a detail side elevation looking from especially to automatic grinding machines of the right to left in Figure 1. type disclosed in my application Serial No. 599,- Figure 5 is a vertical section on the line 5-5 782 filed March 10, 1932. of Figure 3.

5 Primarily the invention has for an object to Figure 6 is adetail view hereinafter referred to. 5

provide an automatic feeder and work rest for Figure 7 is a detail view of the adjustable stud delivering stock from a magazine to its position for the synchronizing arm. to be worked upon by the grinding wheel, and Figure 8 is a detail section on the line 33 of then to deliver it from the machine. Figure 1 showing the gear train to the cam shaft.

Further it is an object to provide an automatic Figure 9 is a front elevation and part section of 10 feeder which is rapid in its action, rugged in its a portion of the machine. construction, is so designed that it will work in Figure 10 is a detail view showing a modified harmony with the driving spindles of the centerway of driving the cam shaft from the mutilated less grinder disclosed in my application aforesaid. gear.

Another object is to provide a feeder of the In the drawings in which like numbers and letrotatable wheel type whose wheel is provided with ters of reference indicate like parts in all the figa series of work rests, which provision allows ures, l represents the base of the machine on larger lots of hearings to be ground without rewhich is mounted the grinding wheel 2 and which grinding the work rests than has heretofore been has a pivot 3 for the pivot shaft 4 of the tail stock possible. table 5. The table 5 has dovetailed ways 6 to Another object is to provide a rotatable wheelreceive and guide the slide 8. The slide 8 is type feeder which, while the work is being opermoved toward and from the wheel 2 by a feed ated upon by the grinding wheel, is rigidly locked screw (not shown) passing through the apron 8 against movement. and threaded into the apron l as in my applica- Further, it is an object to provide a feeder with tion aforesaid, the screw being operated by the 25 cylindrical work rests which can be removed to hand wheel l0 (Figure 1). All of the foregoing change sizes when desired. 6 parts may be of the same construction as the Further, it is an object to provide a feeder with corresponding parts in my application aforesaid. multiple work rests which will handle work both Carried on the slide 8 are bearings II for the for internal and external grinding. driving spindle l2, one end of which has a flanged 30 Further, it is an object to provide a feeder which 0011a! While the 9nd adjacent the Wheel 2 has will locate the work to position by a synchronizer a driving ad M to n a t d f th piece which is adjustable to allow work to be ground of Work to be groundone-eighth smaller and one-eighth larger than The Spindle is driven by Sprocket and chain work rests, I5 from a suitably located counter shaft Ii 35 Other object il in part be obvious and in mounted in bearings H beneath and on the slide part b pointed out her i ft 8 and driven in any suitable way from a prime To the attainment of the aforesaid objects and movmg shaft P Shown) of m ends, the invention still further resides in the 1s aqcam whose shaft 1s Smtably mountefi 40 novel details of construction, combination and on the slide 8. The cam has an outer concentric 40 arrangement of parts, all of which will be first grow? an Inner cmcentnc groove fully described in the following detailed descripmergmg ne wlth h The 9 effects tion, then be particularly pointed out in the apt plagmg i wltgdrawmg of spmdle head f oand romtewor. 4.5 gggiii zfi g x gg ig gs gg E to the ac I The cam I8 is driven from a cam shaft 24 that 5 Figure constitutes a p1 an'view of so much is held in bearings 25 beneath the slide 8 by spiral ears 22--23 and acts on the spindle I! through I of grmdmg machme of the type of my apphca" fine medium of a bell-crank lever 43-45 whose tion aforesaid as is necessary to show the present vent. roller 44 works in the grooves I92ll and whose in l fork rollers work in the flanged collar I3. The 50 Figure 2 IS a detail vertical cross section on the lever 4345 is mounted on a stud 42 on the top line 2-2 of Figure l. of the slide 8.

Figure 3 is a detail enlarged cross section on the Another bearing standard 26 is mounted on the line 33 of Figure 1, the gear train to the cam slide 8 in alignment with bearings H and carries shaft being omitted. the thrust spindlell and its immediately'asso- 55 operates spindle I2;

ciated parts which are the front sleeve 30, spring 32 and the rear sleeve 3i, the sleeve and head 28 of the spindle having a thrust bearing 29.

The sleeve Si is advanced and withdrawn by a cam and lever device similar to that which The spindle 2'I has a collar 34 pinned to its outer end against which the flanged collar 33 of the sleeve 3i abuts so that the cam and lever system may withdraw the head 28 from the work when it is to be discharged and a new piece is to be brought into position.

The cam which operates the thrust spindle 21 is indicated by 35 and its shaft 39 is mounted on the slide 8. The shaft 39 is driven from shaft 24 in the same manner as shaft 2i i. e., by spiral gears 40-4. The cam 35 has an outer concentric groove 36, an inner concentric groove 37 and an intermediate groove 38, the latter merging with grooves 363'I at its ends while the grooves 36-31 at their other ends merge with one another. The spindle sleeve 3i is moved longitudinally in the bearing 26 by a second bellcrank lever 43-45, pivoted on a second stud 02 and having rollers 49 and 46 to engage the grooves of cam 35 and the groove of collar 33 respectively. The cams I8 and 35 are so timed that the heads I4 and 28 move apart simultaneously to release the Work, but not until cam 35 through its groove 38 has first released pressure on head 20 by moving sleeve'3I outwardly to release the tension of the spring 32.

The cam shaft 28 is driven from the spindle I2 through a suitable gear train, which also drives the feed wheel that takes the work from a magazine, locates it between spindle heads M and '28 and by the rotation of said heads is itself placed and held in position on the work rests, as will later more fully appear.

A master driving spur gear 47 on the spindle I2 meshes with a spur gear 48 on stud 49 that is secured at 50 in a bearing 5|. The gear 40 may have a bearing bushing 52 if desired and it is interlocked at 54 with the continuously rotating element 53 of a one-revolution-and-stop clutch mechanism, the driven element of which comprises a mutilated spur gear 59. The elements 53 and 59 have suitable bushings and -65 on a spur gear 66 whose shaft 61 is mounted in a bearing 68 extended from the side of the bearing 69 for the stub shaft 89 of the feed .wheel 90.

Pivoted at II on the support-5I is a finger I0 having a beveled end 86 to release the key 5I from element 53 after each revolution of the element 59. The finger I0 is held in its operating position by a spring 12 secured to it and to a post I3. A bracket 14 is secured to the support 5| and has an opening'through which. the clutch control bar 15 passes and with which bracket it has a pin and slot 19 connection. The bar I5 has a head 11 and an abutment I6, the latter engaging the finger I0 when the bar I5 is moved to the right in Figure 3 to release the key 51. A spring I8 moves the bar I5 to free finger I0. This act is accomplished as the operator turns the hand wheel I0 to move slide 8 away from wheel 2. (The movement of slide 8 and wheel 2 apart may be done by automatic mechanism which forms no part of the present invention, if the invention is being used on a wholly automatic machine.)

The bar I5 may have a one-way-hinged dog 82 pivoted at M to engage a similar dog 83 hinged at 89 to the base I of the grinding wheel assembly. The dog 83 being held back by a stiff relief spring 85 of greater tension than that of the finger spring I2 but of such tension that it will allow dog 83 to give when pin 80 is engaged at left-hand end of slot I9 (Figure 3), should the slide 8 be run back too far.

A spur pinion 81 is secured on the shaft 61 and meshes with a spur gear 88 on the feed wheel shaft 89 to move the feed wheel one step at a time as gear 59 operates gear 66, as will 'later more fully appear.

The feed wheel 90 has a plurality of circular sockets 9i (six being shown, but more or less may be provided as desired), for the circular bodies 92 which carry the work rests 94-95, the bodies being ,held in place, if desired, by screw keys 93 (Figure 2). The wheel 90 also has a set of synchronizing or looking notches 96 with which the tip 91 of the finger 98 of the synchronizer arm 99 engages. The arm 99 and its finger 90 move as one on a pivot I00 whose eccentric shank IOI is held in a bearing extension I02 by a set screw I03 (see Figure 7).

A synchronizing cam I04 is mounted on shaft 24 and cooperates with a connecting rod pivoted at I06 to arm 99 and having a strap I05 around the cam I04. The strap I05 has a tubular extension I09 in which is the shank I08 of a buffer plate I01 and a tension spring IIO. An adjusting screw III is provided for the spring IIO to allow lost motion in the connection between cam I04 and wheel 90 while maintaining engagement of tip 91 with wheel 90 and notch 96.

The work pieces I23 are delivered to the high side of the wheel 90 by a magazine H2 and are guided from there to the wheel 2 by a top guide II3. They are delivered when finished into an off-take chute II4 to which they are guided from the wheel 90 by a lower guard II5.

Motion may be imparted to the shaft 24 directly from gear 59'through a sprocket and chain connection I25, I26, I21 (Figure 10) or it may be done by providing a gear II6 on. a stub shaft III to mesh with gear 59, the gear I I6 having locking plates H8 and being similar to gear 66. The gear IIB meshes with agear II9 on a shaft I20, supported at I2I, and in turn meshing with a gear I22 on shaft 24 (Figure 8).

In the machine depicted in Figures 1 to 9, inclusive, the gear 59 has half the number of teeth of gears 66 and H6 so that one revolution of gear 59 imparts a half revolution to gears 66 and H6. The ratios between gears H6, H9

and I22 are such that one-half revolution of gear II6 imparts one revolution to shaft 24.

The ratios of gears 86-81-88 are such that one-half revolution of gears 66-8! imparts a to position for grinding and another has just been ground. The operator turns back wheel I0 to draw slide 8 away from grinding wheel 2. I

This engages 92 and 83 and pulls bar 15 to the right in Figure 3, thereby releasing key 51 which, as soon as slot 56 lines up with it, will lock elements 53 and 59 together. In the meantime 82 and 83 will become disengaged and springs 12 and 18 will return finger and bar so that key 51 will be released again as one revolution of gear 59 is made.

As gear 59 begins to turn and just before cam H14 releases finger tip 91 from notch 96, cam groove 38 will cause lever 4345, associated with it, to move sleeve 3| to the right to release tension of spring 32 and then engage collar 34.

As gear 59 moves farther, cams l8 and will move spindles I2 and 21 apart, and cam I04 will release finger tip 91 from notch 96. By this time teeth on gear 59 will engage gear 66 and cause wheel 90 to be turned one step. There-' after as gear 59 completes its single revolution cam I04 will cause 91 to enter the adjustment notch 96, and then cams l8 and 35 will move spindle heads M28 into engagement with the newly placed piece of work.

As wheel 99 moves its step just described the finished piece will drop onto chute H4 and be discharged from the machine. The operator then screws in on screw wheel III to move slide 8 toward grinding wheel to bring the new piece of work against the wheel 2 and the cycle of operation is complete.

It should be understood that in the machine illustrated the axis of the spindles I2 and 21 is preferably eccentric to that of the work and the work rests, as in the machine of my application aforesaid, so the spindles in rotating constantly tend to keep the work properly seated on the rests 94-95.

The rotatable feed wheel with its endless number or series of work rests, which is moved or indexed step by step to the grinding position, when it arrives at the grinding position locates itself accurately for the support of the work to be ground and supports that work during the entire grinding operation. When the driving spindles come in contact with the work all of the support of the work is taken by the work rest during the grinding operation due to the driving spindles being set oil-center of the work which they drive, thus automatically drawtween the wheel and support from and toward one another, a work magazine, a rotatable feed wheel, having a plurality of pockets in its circumference, a removably mounted work rest in each pocket open at the periphery of the wheel and arranged to receive the work from the magazine, work-end-engaging spindles adjacent the grinding wheel, means to lock the feed wheel with the work in position for grinding, and means to unlock the wheel and impart to it a step-by-step rotation at intervals to deliver new work to and remove finished work from the spindles.

' 2. In a grinder, a grinding wheel and a support,

a removably mounted work rest in each pocket f open at the periphery of the wheel and arranged to receive the work from the magazine, workend-engaging spindles adjacent the grinding wheel, means to lock the feed wheel with the work in position for grinding, means to unlock the wheel and impart to it a step-by-step rotation at intervals todeliver new work to and remove finished work from the spindles, and means effected by the relative movement between the grinding wheel and said support for controlling action of said feed wheel unlocking and rotating means.

3. In a grinding machine having-a grinding wheel and work-holding spindles, the combination with the work-holding spindles, of a workfeeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work.

4. In a grinding machine having a grinding wheel and work-holding spindles, the combination with the work-holding spindles, of a workfeeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then wtihdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, and means to move relatively the grinding wheel and workholding spindles to and from each other, and means governed by said relative movement for controlling the action of said means first to release the pressure, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work.

5. In a grinding. machine, a grinding wheel and a support and means to efiect relative movement between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, and means governed by the relative movement between said wheel and support in one direction for conveying work blanks one at a time to said spindles and removing finished work from the spindles.

6. In a grinding machine, a grinding wheel and a support and means to eiTect relative movement between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being ground by said grinding wheel and to remove the finished work from the spindles, means for driving said spindles, means including an intermittent clutch device and'a gear train between said rotatable wheel and said driving means for actuating said rotatable wheel and means for efiecting the intermittlng action of said clutch device.

7. In a grinding machine, a grinding wheel and a support and means to effect relative movement .between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being ground by said grinding wheel and to remove the finished work from the spindles, means for driving said spindles, means including a gear train and a one-revolution-and-stop clutch device connecting said driving means with said rotatable wheel to operate same, and means governed by said relative movement between said grinding wheel and said support for controlling said clutch device.

.. 8. In a grinding machine, a grinding wheel and a support and means to effect relative movement between said wheel and support toward and from one. another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable-wheel carrying rests and adapted to receive a blank-from the magazine, convey it to said spindles and support it while being ground by .said grinding wheel and to remove the finished between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles andsupport it while being ground by said grinding wheel and to remove the finished work from the spindleazmeans for driving said spindles, means including a gear train and a onerevolution-and-stop clutch device connecting said driving means with said rotatable wheel to operate same, means governed by said relative move- "ment between said grinding wheel and said support for controlling'said clutch device, said spindles including a yieldable member and engaging the work at its ends, and-means for releasing the pressure of the yieldable member on the work before-the rotatable wheel begins to turn.

10. In a grinding machine, a grinding wheel and asupport' and means to effect relative movementbetween said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine 'for work blanks, means governed byithe relative movement between said wheel and support in one direction for conveying work blanks one at a time to said spindles and removingfinished work from the spindles; said spindles includingra yieldable'member andengaging the work at its ends, and means for reileasing the pressure of the yieldable member on the work without disengaging the spindles 'from the work andbeiore said governed means begins to act, and for thereafter separating the spindles to releasethe' finished work and then bringing them together again to hold a newly placed blank in position for grinding.

' 1I.In a grinding'machine, a'grinding wheel and a support'and means to effect relative movement between said wheel and support toward for releasing the pressure of the yieldable member on the work without disengaging said yieldable member from the work and before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for grindmg.

12. In a grinding machine, a grinding wheel and a support and means to effect relative movement between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being ground by said grinding wheel and to remove the finished work from the spindles, means for driving said spindles, means including a gear train and a onerevolution-and-stop clutch device connecting said driving means with said rotatable wheel to operate same, means governed by said relative movement between said grinding wheel and said support for controlling said clutch device, said spindles including a yieldable member and engaging the work at its ends, and means for releasing the pressure of the yieldable member on the work before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in pos tion for grinding.

13. In a grinding machine having a grinding wheel and work-holding spindles, the combina- .tion with the work-holding spindles, of a workfeeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, means to lock said work-ieeding wheel while the work is being ground, and means to release said locking means when the feeding wheel is to be turned.

14. In a grinding machine having a grinding dles with yieldable pressure. and means first to release the pressure without d sengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, and means to move I relatively the grinding wheel and work-holding spindles to and from each other, means govemed by said relative movement for controlling the action of said means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, means to lock said work-feeding wheel while the work is being ground, and means to release said locking means when the feeding wheel is to be turned.

15. In a grinding machine, a grinding wheel and a support and means to effect relative movement between said wheel and support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being ground by said grinding wheel and to remove the finished work from the spindles, means for driving said spindles, means including an intermittent clutch device and a gear train between said rotatable wheel and said driving means for actuating said rotatable wheel and means for effecting the intermitting action of said clutch device, and means to lock said rotatable wheel while the work is being ground and to release said wheel when it is to be turned. 7

16. In a grinding machine having a grinding wheel and work-holding spindles, the combination with the work-holding spindles of a work-feeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdray the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with' a new piece of work, means to lock said work-feeding wheel while the work is being ground, and means to release said locking means when the feeding wheel is to be turned, said looking and releasing means comprising a notch in the feeding wheel, an arm having a finger to fit said notch, a cam and connecting rod for operating said arm and finger and means to actuate said cam in harmony with the actuation of said feeding wheel.

1'7. In a grinding machine having a grinding Wheel and work-holding spindles, the combination with the work-holding spindles of a work-feeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, and means to move relatively the grinding wheel and work-holding spindles to and from each other, and means governed by said relative movement for controlling the action of said means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece. of work, means to lock said work-feeding wheel while the work is being ground, and means to release said locking means when the feeding wheel is to be turned,

said locking and releasing means comprising a notch in the feeding wheel, an arm having a finger to fit said notch, a cam and connecting rod for operating said arm and finger and means to actuate said cam in harmony with the actuation of said feeding wheel.

18. In a grinding machine having a grinding wheel, a slide, means to move said slide toward and from said wheel, a pair of work-end-engaging and holding spindles mounted to rotate in bearings on said slide, means to drive at least one spindle, yieldable means for holding one of said spindles against the work, cam and lever mechanisms for moving said spindles along their axes toward and from the work, the cam which moves the spindle that has the yieldable means having provision for releasing the pressure of the yieldable means before beginning the movement of that spindle away from the work, a cam shaft geared to said cams, a work-blank-holding magazine, a rotatable wheel having a plurality of work rests and mounted on said slide to receive blanks from said magazine and to carry them to a position to be engaged by said spindles and be worked on by said grinding wheel, and means to impart a step-by-step movement to said rotatable wheel and said cam shaft.

19. In a grinding machine having a grinding wheel, a slide, means to move said slide toward and from said wheel, a pair of work-end-engaging and holding spindles mounted to rotate in bearings on said slide, means to drive at least one spindle, yieldable means for holding one of said spindles against the work, ,cam and lever mechanisms for moving said spindles along their axes toward and from the work, the cam which moves the spindle that has the yieldable means having provision for releasing the pressure of the yieldable means before beginning the movement of that spindle away from the work, a cam shaft geared to said cams, a work-blank-holding magazine, a rotatable wheel having a plurality of work rests and mounted on said slide to receive blanks from said magazine and carry them to a position to be engaged by said spindles and be worked on by said grinding wheel, and means to impart a step-by-step movement to said rotatable wheel and said cam shaft, said last-named means comprising a' gear train including an intermittent clutch connecting the driving spindle with said rotatable wheel and with said cam shaft, and means to control the action of said clutch.

20. In a grinder, a grinding wheel and asupport, and means to effect relative movement between the wheel and support from and toward one another, a work magazine, a rotatable feed wheel, having a plurality of pockets in its circumference, a work rest in each pocket arranged to receive the work from the magazine, work-endengaging spindles adjacent the grinding wheel, means to lock the feed wheel with the work in position for grinding, means to unlock the wheel 1 an endless series of work rests, means for moving said work rests from a position to receive work from said magazine to a position for locating work with relation to said spindles and grinding wheel and means governed by the relative movement between said wheel and said support for actuating said work-rest-moving means for the purposes described.

22. In a grinder, a grinding wheel and a support and means to effect relative movement between said wheel and said support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, and an endless series of work rests, means for moving said work rests from a position to receive work from said magazine to a position for locating work with relation to said spindles and grinding wheel, means governed by the relative movement between said wheel and said support for actuating said work-rest-moving means for the purposes described and means cooperative with said work rests for holding them in normal operative position while the work is being ground;'

23. In a grinder, a grinding wheel and a support and means to effect relative movement between said wheel and said support toward and from one another, work-holding spindles carried by the support, a magazine for work blanks, and an endless series of work rests, means for moving said work rests from a position to receive work from said magazine to a position for locating work with relation to said spindles and grinding wheel, means governed by the relative movement between said wheel and said support for actuating said work-rest-moving means for the purposes described, means cooperative with said work rests for holding them in normal operative position while the work is being ground and means cooperative with said last-named means for advancing or retarding the position of said work rests with respect to the normal for over and under size work.

24. In a grinding machine, a grinding wheel and a support, work-holding spindles carried by the support, a magazine for work blanks, means including work supports for conveying work blanks one at a time to said spindles and removing finished work from the spindles, said spindles including a yieldable member and engaging the work solely at its ends, and means for releasing the pressure of the yieldable member on the work without disengaging said spindles from the work and before the said conveying means begins to act, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for grinding.

25. In a grinding machine, a grinding wheel, a support, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being ground by said grinding wheel and to remove the finished work from the spindles, means for driving said spindles, means including an intermittent clutch device for actuating said rotatable wheel, means for effecting the intermitting action of said clutch device, said spindles including a yieldable member and engaging the work at its ends, and means for releasing the pressure of .the yieldable member on the work without disengaging said spindles from the work and before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for grinding.

26. In a grinding machine, a grinding wheel and a support, work-holding spindles carried by the support, a magazine for work blanks, means including work supports for conveying work blanks one at a time to said spindles and removing finished work from said spindles, said spinby the support, a magazine for work blanks, means including work supports for conveying work blanks one at a time to said spindles and removing finished work from the spindles, said spindles including a yieldable member and engaging the work solely at its ends, and means for releasing the pressure of the yieldable member on the work without disengaging said spindles from the work and before the said conveying means begins to act, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for being worked on.

28. A support, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being worked on and to remove the finished work from the spindles, means for driving said spindles, means including an intermittent clutch device for actuating said rotatable wheel, means for effecting the intermitting action of said clutch device, said spindles including a yieldable member and engaging the work at its ends, and means for releasing the pressure of the yieldable member on the work without disengaging said spindles from the work and before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for being worked on.

29. A support, work-holding spindles carried by the support, a magazine for work blanks, means including work supports for conveying work blanks one at a time to said spindles and removing finished work from said spindles, said spindles adapted to engage the work solely at its ends and including a yieldable member, a cam actuated meansfor releasing the pressure of said yieldable member on the work without disengaging the spindles from the work and subse-' quently separating said spindles to release the work therefrom and thereafter bring the spindles together again to hold a newly placed blank in position for being worked on.

30. A work magazine, a rotatable feed wheel having a plurality of pockets in its'circumference, a removably mounted work rest in each pocket open at the periphery of the 'wheel and arranged to receive the work from the magazine, work-end-engaging spindles, means to lock the feed wheel with the work in position for being' worked on, and means to unlock the wheel and impart to it a step-by-step rotation at intervals to deliver new work to and remove finished work from the spindles.

31. A work magazine, a rotatable feed wheelhaving a plurality of pockets in its circumference, a removably mounted work rest in each pocket open at the periphery of the wheel and arranged to receive the work from the magazine, work-endengaging spindles; means to lock the feed wheel with the work in position for being worked on, and means to unlock the wheel and impart to it a step-by-step rotation at intervals to deliver new work to and remove finished work from the spindles, and means for controlling the action of said feed wheel unlocking and rotating means.

32. The combination with work-holding spindles, of a work-feeding wheel having a plurality of work rests spaced about-its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, their rotate the feed wheel one step and then return the spindles to engagement with a new piece of work.

33. The combination with work-holding-spindles, of a work-feeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, and means for controlling the action of said workholding means first to release the pressure, then to withdraw the spindles from the work, then to rotate the feed wheel one step, and then to return the spindles to engage a new piece of work.

34. A support, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheelcarrying rests and adapted to receive a. blank from the magazine, convey it to said spindles and support it while being worked on, and to remove the finished work from the spindles, means for driving said spindles, means including a gear train and a one-revolution-andstop clutch device connecting said driving means with said rotatable wheel to operate same, and means for controlling saidclutch device.

35. A support, work-holding spindles carried by the support, a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine,-convey it to said spindles and support it while being worked on, and to remove the finished work from the spindles, means for driving said spindles, means including an intermittent clutch device for actuating said rotatable wheel, means for effecting the intermitting action of said clutch device, said spindles including a yieldable member and engaging the work at its ends, and means for releasing the pressure of the yieldable member on the work without disengaging said yieldable member from the work and before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for being worked on.

36. A support, work-holding spindles carried by the support. a magazine for work blanks, a rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being worked on, and to remove the finished work from the spindles, means for driving said spindles, means including a gear train and a one-revolution-andstop-clutch device connecting said driving means with said rotatable wheel to operate same, means for controlling said clutch device, said spindles including a yieldable member and engaging the work at its ends, and means for releasing the pressure of the yieldable member on the work before the rotatable wheel begins to turn, and for thereafter separating the spindles to release the finished work and then bringing them together again to hold a newly placed blank in position for being worked on.

37. The combination with work-holding spindles, of a work-feeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindles to engagement with a new piece of work, means to lock said work-feeding wheel while the work is being worked on, and means to release said locking means when the feeding wheel is to be turned.

38. The combination with work-holding spindles, of a work-feeding wheel having a plurality of work rests spaced about its periphery, and mounted to convey Work into and from position with respect to said spindles, means to hold the work between the spindles with yieldable pressure, and means first to release the pressure without disengaging the spindles from the work, then withdraw the spindles from the work, then rotate the feed wheel one step and then return the spindlesto engagement with a new piece of work. means to lock said work-feeding wheel while the work is being worked on, means to release said locking means when the feeding wheel is to be turned, said locking and releasing means comprising a notch in the feeding wheel, an arm having a fin er to fit said notch, a cam and connecting rod for operating said arm and finger, and means to actuate said cam in harmony with the actuation of said feeding wheel.

39. A pair of work-end-engaging and holding spindles mounted to rotate in bearings on said support, means to drive ,at least one spindle, yieldable means for holding one of said spindles against the work, cam and lever mechanisms for moving said spindles along their axes toward and from the work, the cam which moves the spindle that has the yieldable means having provisions for releasing the pressure of the yieldable means before beginning the movement of that spindle away from the work, a cam shaft geared to said cams, a work-blank-holding magazine, a rotatable wheel having a plurality of work rests and mounted on said support to receive blanks from said magazine and carry them to a position to be engaged by said spindles and be worked on, and means to impart a step-by-step movement to said rotatable wheel and said cam shaft.

40. A pair of work-end-engaging and holding spindles mounted to rotate in bearings on said support, means to drive at least one spindle, yieldable means for holding one of said spindles against the work, cam and lever mechanisms for moving said spindles along their axes toward and from the work, the cam which moves the spindle that has the yieldable means having provisions for releasing the pressure of the yieldable means before beginning the movement of that spindle away from the work, a cam shaft geared to said cams, a work-blank-holding magazine, a rotatable wheel having a plurality of work restsand mounted on said support to receive blanks from said magazine and carry them to a position to be engaged by said spindles and be worked on, means to impart a step-by-step movement to said rotatable wheel and said cam shaft, said last named means comprising a gear train including an intermittent clutch connecting the driving spindle with said rotatable wheel and with said cam shaft, and means to control the action of said clutch.

41. A support, a work magazine, a rotatable feed wheel having a plurality of pockets in its circumference, a work rest in each pocket arranged to receive the work from the magazine,

work-end-engaging spindles, means to lock the feed wheel with the work in position for being operated on, means to unlock the wheel and impart to it a step-by-step rotation at intervals to deliver new work to and remove finished work from the spindles, and means cooperative with said locking means for holding the feed wheel slightly in advance of or retardedfrom its normal positions as desired for over and under size work.

42. A support, work-holding spindles carried by the support, a magazine for work blanks, and an endless series of work rests, means for moving said work rests from a position to receive work from said magazine to a position for locating work with relation to said spindles, means for actuating said work-rest-moving means, means cooperative with said work rests for holding them in normal operative position while the work is being worked on, and means cooperative with said last named means for advancing or retarding the position of said work rests with respect to the normal for over and under size work.

43. A support, work-holding spindles carried by the support, ,a magazine for work blanks, a

rotatable wheel carrying rests and adapted to receive a blank from the magazine, convey it to said spindles and support it while being worked on, and to remove the finished work from the spindles, means fordriving said spindles, means including an intermittent clutch device and a gear train between said rotatable wheel and said driving means for actuating said rotatable wheel and means for effecting the intermitting action of said clutch.

44. In a grinding machine, a grinding wheel and a support, work-holding spindles carried by .the support, means for conveying work blocks one at a time to said spindles and removing finished work from the spindles, one of said spindles comprising a thrust spindle, a front sleeve on said thrust spindle, said thrust spindle having a work engaging head against which said front sleeve operates, a rear sleeve on said thrust spindle, a spring between said sleeves, a cam actuated means for moving said rear sleeve and thrust spindle first to release the spring pressure and then move said thrust spindle lengthwise whereby pressure on said front sleeve is released before said thrust spindle is moved to disengage the work.

45. In a grinding machine, a grinding wheel and a support, work holding spindles carried by the support, a magazine for work blanks, indexing means including work supports for conveying work blanks one at a time to said spindles and removing finished work from the spindles, said spindles having provisions for engaging the work blanks only by end contact therewith, one of said spindles including a yieldable member for apply- 

